Solid diazo salts



Patented Sept. 7, 1937 UNITED (STATES PATENT cries 7 bach-onthe-Main,

Germany, assignors to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Original application May 17, 1933, Serial No. 671,590, now Patent No. 2,067,132. Divided and this application November 27,

1936, Serial No. 113,082.

Claims.

wherein Y stands for halogen, Me stands for a metal of the group consisting of Zn, Cd and Sn,

and m for a number corresponding to the high est valence of the metal signified by Me, and wherein the benzene nucleus may be further substituted.

This application is a division of our co-pending U. S. Patent application Ser. No. 671,590, filed May 17, 1933.

The diazo salts may be obtained by diazotizing unilaterally 1,4-diaminobenzenes, halogenated in the nucleus and being free. from sulfonic acid or carboxylic acid groups, 1. e. by treating the said 1,4-diaminobenzenes with thequantity of mineral acid and nitrous acid, necessary for diazotizing one amino group, and by precipitating the diazo compounds, thus obtained, in the form of stabilized diazo compounds, such as, for instance, zinc chloride-, tin chlorideor cadmium chloride-double salts.

Morgan and Cleage (of. Journal of the Chemical Society, 113, (1918), pages 590 and 596) have transformed 2,6-dichloro-1,4-diaminobenzone in dry acetone solution into 2,6-dichlorobenzene-4-diazo-l-imine by the action of nitrous anhydride. The product, thus obtained, is very unstable. It was not separated in a solid form but, after its formation, it was at once acetylated in the acetone solution and thereby identified.

It could not be foreseen-that halogenated 1,4-

diaminobenzenes could be transformed in a smooth reaction into aminodiazonium salts in the presence of mineral acid and it could, fur thermore, not be foreseen whether these monodiazo compounds could easily be precipitated and whether they would be stable enough for being used on an industrial scale as dyeing salts.

As is known, it is not possible to perform the monodiazotization of para-phenylenediamine in a technical manner. Biilow (cf. Berichte der deutschen chemischen Gesellschaft, 29, (1896), page 2285) describes the unilateral diazotization of nitro-para-phenylenediamine; but it could not be concluded from this literature reference that it would be possible to transform halogenated 1,4-diaminobenzenes into a mono-diazo compound.

In Germany May 21, (01. 260-41 All these diazo salts possess a very good stability, even at higher temperatures. It is, therefore, possible to furnish the dyer, for Whom it is diilicult or at least laborious to carry out the mono-diazotization of the diamines, with monodiazo compounds in a stable form ready for use.

These new solid diazonium salts which may be diluted with the usual admixtures and adjusted to the usual commercial form, are of especial value in the ice color industry.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto, ,the parts being by weight:

(1) 177 parts of 2,6-dichloro-lfl-diaminobenzene are dissolved or suspended in 270 parts of hydrochloric acid of 32.1% strength and 8500 partsof water and diazotized at 10 C. to C. with a solution of 72 parts of sodium nitrite in 300 parts of water. To the diazo solution, there are added 150 parts of a zincchloride solution of 50% by weight and the diazonium zinc chloride double salt of the following probable formula:

' Heep-NP Z1101, 1 2 Q is salted out by addition of sodium chloride, worked up as usual and, if desired, adjusted to the usual commercial form by addition of, for instance, anhydrous sodium sulfate or partly dehydrated aluminium sulfate. The salt is very stable and easily soluble.

The precipitation may also be effected by means of a zinc chloride solution which has a small content of SnCLi.

In an analogous manner, there may be obtained the diazonium zinc chloride double salts of other halogen-lA-diaminobenzenes, for instance, of 2-ch1oro-, 2-ch1oro-5-methy1- and 2- chloro-fi-bromo-lA-diaminobenzene.

(2) 222 parts of 2-chloro-6-bromo-1,4-diaminobenzene are diazotized as described, in EX- ample (1). The diazo compound is precipitated by means of 120 parts of crystallized cadmium chloride and sodium chloride and worked up as usual. The cadmium chloride double salt is very stable.

(3) To the diazo solution, prepared according to the statements in Example (1) from 177 parts of 2,6-dichloro-lA-diaminobenzene, there is added a solution of 140 parts of anhydrous tintetra-chloride or of the corresponding quantity of sodium-tin-chlori-de of the composition NazSnCla-HzO in water and the precipitation of the diazonium tin double salt is completed by addition of sodium chloride. Thereupon, the Whole is filtered and the product is worked up as usual. The tin chloride double salt forms 5 a feebly brownish powder and corresponds probably to the following formula:

nm-Q-aw- "Snell! We claim:

1. The solid diazo salts corresponding to the 15 general formula:

wherein Y stands for halogen,. Z stands for one of the group consisting of hydrogen, halogen and alkyl, Me stands for a metal of the; group consisting of Zn, Cd and Sn, and m for a num- 25 her corresponding to the highest valence of the metal signified by Me, being very stable and easily soluble in water.

2. The solid diazo salts corresponding to the 30 general formula:

wherein Y stands for halogen, Z stands for one wherein Me stands for a metal of the group consisting of Zn, Cd and Sn, and m for a number. corresponding to the highest valence of the metal signinfied by Me, being very stable and easily soluble in water.

4. The solid diazo salt corresponding to the being very stable and easily soluble in water.

5. The solid diazo salt corresponding to the formula:

being very stable and easily soluble in water. KARL SCHNITZSPAHN. WILHELM KOCH. 

